Steam-boiler furnace.



No. 707,865 Patented Aug. 26, I902. HQH. PATTERSON & J. T. BURKE.

STEAM BOILER FURNACE.

l App1ication filed Dec. 24, 1901.)

(No Model.)

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UNrrnD STATES PATENT OFFICE.

l-IERMON HENRY PATTERSON, OF NORFOLK, AND JOHN THOMAS BURKE,

OF OMAHA, NEBRASKA.

STEAM-BOILER FURNACE.

SPECIFICATION forming part of Letters Batent N 0. 707,865, dated August 26, 1902.

Application filed December 24, 1901. derial No. 87,085. (No model.)

To all; whom, it may concern:

Be it known that we, HERMoN HENRY PAT- TERSON, residing at Norfolk, in the county of Madison, and JOHN THOMAS BURKE, residing at Omaha, in the county of Douglas, State of Nebraska, citizens of the United States, have invented certain new and useful Improvements in Steam-Boiler Furnaces; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same;

Our invention relates to improvements in steam-boiler furnaces; and it consists in a furnace of this character providedwith means for maintaining different desired pressures within the fire-box and furnace-fines to vary the heat-producing capacity of the furnace and its efiect upon the contents of the'boiler.

It further consists in certain other novel constructions, combinations, and arrangements of parts, as will be hereinafter described and claimed.

In the accompanying drawings, Figure 1 is a vertical longitudinal central section through a furnace, showing a steam-boiler in operation mounted therein. Fig. 2 is a detail horizontal sectional view of a portion of the airsupply mechanism.

The present invention has for its object the production of a steam-boiler furnace in which the conditions in the combustion-chambers of the same are regulated to secure the most complete and perfect combustion of the fuel used,'the arrangements being such as to enable us to produce on the Heating-surfaces of the boiler such conditions that the maximum amount of heat may'be'extracted from the products of combustion, and the said conditions may be varied and regulated automatically or by hand.

The invention is based on the well-known facts that, first, combustion is more intense, and consequently more perfect and complete, in proportion to the pressure under which the combustion takes place and also that the number of heat units which may be obtained from a given quantity of the gases in the combustion-chamber at any given initial tempera- 5o ture is proportionate to the pressure upon said gases.

1 It will be obvious that the above results may be obtained by subjecting the combustion-chambers and heating-surfaces of the furnace to suitable pressure consistent with practical application.

In the drawings we have shown a practical mechanism for attaining the desired results, in which the boiler 1, of the ordinary type, mounted upon the usual settings in the furnace, is provided with the usual stack and stack connections. The means for regulating pressure in the combustion-chamber and furnace-fines comprises a series of air-pipes 3, which extend into the furnace through the rear wall 2 thereof, passing through the coinbustion-chamber A of the furnace and through the bridge-wallo, their inner open ends connecting with the ash-pit of the furnace beneath the grate 6. The outer ends of the pipes 3 are connected just outside the rear wall 2 of the furnace with a header or large pipe 7, which is arranged transversely with respect to the furnace. The header 7 is connected with a pressure-regulating mechanism, such as a fan or blower 8. (Shown in Fig. 1 of the drawings.) Such fan may be driven by any suitable means and is capable of forcing air into the header 7 and through the pipes 3 into the ash-pit of the furnace. In the threat 0 the blower, just to one side of the header 7, is arranged a weighted valve or damper 10, which is capable of controlling the amount of air forced through the pipes 3 or the pressure thereof. In the breeching 9 of the smokestack is arranged a second damper or valve 11, which is also weighted and is capable of controlling the escape of the smoke and products of combustion into the stack. Both of the dampers l0 and 11 are arranged so that when turned across their respective passages they will almost but not entirely close the same.

At any suitable point upon the boiler is arranged a hollow casing 12, within which works a piston 13, having a piston-rod14t extending outside the casing through an ordinary packing-box. The steam-pressure of the boiler against the piston tends to push the pistonrod '14: outwardly against a lever 15, which is fulcrumed at 16 upon a suitable standard or arm of the casing 12, the opposite end of the arm 20, secured to the spindle'of the damper 10. The construction of the parts issuch sure received from the fan 8;

that when the boiler-pressure .rises above a .point which is determined by the position of v the weight 17 on the lever 15 the said lever will be raised and the cord 18 will be slackened,

, so that the weighted side of the valve will drop, thereby partly closing 0E the air-pres- Another cord 21 is fastened to the lever adjacent to the cord 18 and passes thence upwardly over a pulley 22 and thence to a crank-arm 23, which is fastened to one end of the spindle of the damper 11. The arrangement is such that when the lever 15 is raised by the boiler-pressure upon the piston 13 the cord 21 will be slackened and the weighted side of the daniper 11 will drop, thereby opening more fully the passage through the breeching 9.

The crank-arm 23 of the damper 11 preferably extends each side of the spindle of said damper, one end being secured, as just described, to the cord 21, while the other end projects a little bit beyond the forward end of the furnaceand is pivotally secured to a rod or bar 24.

The rod 24: is provided with a series of notches 25 in one edge thereof, which are adapted to engage a projection 26 on the end'of the boiler 1. The position of the valve 11 can thus be alteredby-hand by adjusting the bar or rod 24 at different heights upon the boiler-front.

The fire-box or fuel-chamber andthe ashpit of the furnace are provided with doors 27, which are made to fit very snugly in place when closed, so as to prevent air from escaping through the same under the pressure within to any appreciable degree.

In" usingthe mechanism above described the weight 17 is adjusted to position on the lever 15 such that it will just balance the required boiler-pressure. The damper 11 in the breeching is then opened by raising the rod 24 and holding it in position by bringing one of its notches 25 in contact with the projection 26. The fires are then started upon the grate and the fan 8 is put in motion, being driven in any suitablemann'er. As soon as the fan is started the doors 27, which are, as above intimated, made as nearly airtight as possible, are closed, so that all air entering the furnace must pass through the pipes 3 and the header 7. The rod 24 may then be lowered and close the damper 11, so that only a comparatively, small opening is left through the breeching. The air driven in by the fan passes through the pipes 3 in the combustion-chamber, becoming heated thereby and ready for introduction into the ashpit and fire-box. Since the air thus driven into the furnace is more than can escape under normal pressure past the damper 11, it will be seen that a compression is formed in the fire-box, combustion-chamber, and flues of the furnace until the pressure is suificient to drive the products of combustion past the damper 11 at a rate equal to that at which the air is forced into the furnace through the fan. Now if the steam-pressure in the boiler rises above the desired point the piston 13 compression in the furnace may be relieved sufficiently to prevent the fire from blowing out said doors by raising the rod 24,and there by opening the damper 11. Although the pressure is thus relieved by opening the damper 11, the influx of heated air through the pipes 3 is sufficient to prevent air from entering the doors while they are open.

While the mechanism illustrated is a practical one for the desired purpose, it will be obvious that the various parts thereof may be considerably varied without departing from the spirit of the invention, the essential features of which are the provision of means for forcing air into the furnace for heating said air before it reaches the grate and means for regulating the supply of heated air, as well as means for controlling the escape of the products of combustion from the furnace, so that the heated air forced into the furnace will'maintain a suitable compression therein. In the ordinary natural-draft furnace and in a forced-suction-draft furnace instead of maintaining a pressure in the combustion chambers and on the heating sur faces greater than the atmospheric pressure a less than atmospheric pressure is obtained, and of course the deficiency of pressure is greaterin proportion to the strength of draft, causing a loss in the operation of the furnace. V

Having thus fully described our invention, what we claim as new, and desire to secure by Letters Patent, is-' 1. A steam boiler furnace formed with means for maintaining a pressure within the fire-box and combustion-chamber of the same, comprisinga mechanism for forcing air into the ash-pit of the furnace, means for controlling the amount of air forced in, and means for controllingthe draft in the chimney the said means cooperating so that when less air is allowed to enter the ash-pit, the means in the chimney will be operated to release the pressure somewhat at that point simultaneously, substantially as described.

2. A mechanism for producing and regutoo lating the pressure Within the ash-pit, firebox and combustion-chamber of a furnace comprising piping for introducing air under pressure into the ash-pit, a valve for controlling theamountofairthusintroduced,a checkdamper in the chimney-flue, means for operating the valve and damper simultaneously to increase or diminish the pressure maintained within the fire-box and combustionchamber, substantially as described.

3. Means for producing and maintaining a suitable pressure Within a furnace, comprising a series of pipes passing through the combustion-chamber of a furn ace and the bridgewall thereofinto the ashpit, a blower or other air-forcing means for delivering air to said pipes, a gate or valve for controlling the amount of air introduced into the furnace, a check-damper in the chimney-flue of the furnace, means operated by the boiler-pressure and connected with the said gate and the said check-damper so that when the gate is moved to cut off the incoming supply of air, the damper in the chimney-flue will be correspondingly opened to diminish the back pressure upon the draft at the same time thus diminishing the pressure maintained Within the fire-box and combustion-chamber of the furnace, substantially as described.

4. A mechanism for producing and regulating the pressure Within a furnace comprising a series of pipes passing through the combustion-chamber and bridge-wall of the furnace into the ash-pit, a header for connecting said pipes, ablower for forcing air through the pipes, a gate or valve for controlling the inlet of air to the ash-pit, acheck-damper in the smoke-flue of the furnace, a steam-operated pressure mechanism on the boiler of the furnace connected with the saidinlet-gate and check-damper for causing the increasing or diminishing of the pressure maintained in the furnace, substantially as described.

5. A pressure producing and maintaining mechanism comprising means for forcing air into the ash-pit of a furnace, a gate for controlling the same, a check or damper in'the smoke-flue, a hand-operated lever for operating said check-dam per, a lever operated by the boiler-pressure, cords connecting the said gate and the said check-valve with the said lever so that when the gate is closed the checkdamper Will be correspondingly opened to control the pressure within the combustion-chamber of the furnace, substantially as described. In testimony whereof we hereunto aflix our signatures in presence of two witnesses.

HERMON HENRY PATTERSON.

JOHN THOMAS BURKE. \Vitnesses:

D. O. BARNELL,

II. .T. CoWoILL. 

